The proposed study addresses the NIA pilot research grant program PAR-03-056-#12-calling for preliminary studies examining "factors moderating the rate of age-related changes and risk for adverse events with increasing age." The program announcement is particularly interested in "factors contributing to exceptional healthy aging in humans." We propose: to examine "exceptional healthy aging' through an examination of the trajectory of the syndrome of frailty in a sample of older, initially non-frail, Mexican Americans; and to examine whether positive affect is associated with the delay in onset and progression of frailty for this population. This work is important for 3 reasons. First, the syndrome of frailty has not been studied in older Mexican American populations. Second, this work begins to examine factors that may contribute to a narrowing of health disparities that currently exist between underserved minority groups. Third, the committee on future directions for Behavioral Social Sciences Research at the National Institutes of Health recently recommended that new resources be made available for advancing knowledge on aspects of positive health including mechanisms underlying the health benefits resulting from positive psychological influences. Specific Aims of the proposed research are: 1. Examine the trajectory of the syndrome of frailty using operationally defined criteria, 2. Examine interaction effects for positive affect and age, gender, marital status, and socioeconomic status on the trajectory of the syndrome of frailty, and 3. Examine the mediating effect of positive affect on associations for co-morbidity, cognition, and social support on the trajectory of the syndrome of frailty in a sample of older, initially non-frail Mexican Americans over a 7 year period. Data is from the Hispanic Established Populations for the Epidemiologic Studies of the Elderly (HEPESE), and this data represents 85% of the older Mexican American population in the U.S. Findings from this R03 application will generate data for an R01 application examining cross-national differences and similarities in healthy aging for older Hispanics in the U.S., Mexico, and Latin America. [unreadable] [unreadable]